I don’t wanna be desperate

How do you prevent yourself from trying to call your ex??? I broke up with him and I feel like he didn’t even fight for me. There was no cheating. I did it because I think we just two very different people who like different things and we just didn’t have anything in common and I tried for awhile. Almost a year. He didn’t ask me why. He just said “ok. If that’s what you want” and walked away. I want to call him so bad and ask him why is it so easy for him to get over me Just like that? So I blocked him. Removed him from my Snapchat. All social media. But I still know his number. But I don’t wanna seem like that ex girlfriend that won’t stop call her ex. The way I look it.. he hasn’t tried To reach me to get clarification so why should I? It kinda helps me to not call but now it’s Just eating at me. So how can I keep my mind off from calling him?